The U.S. Senate race in Washington hit critical mass this week. Sen. Patty Murray launched her first negative attack ads against Republican Dino Rossi just as voters have received their ballots for the Aug. 17 primary.

There appears little doubt this is a tight race. Public Policy Polling has a new survey showing that Murray has only a narrow lead over Rossi in a general election matchup, 49 to 46 percent. And that's just about at the poll's margin of error of 2.8 percentage points. (Interestingly, in polling for the primary, the firm finds Murray at 47 percent, Rossi at 33 percent, Didier at 10 percent and Republican Paul Akers at 4 percent. Remember, under Washington's Top Two system, everyone is on the same ballot and the top two finishers advance to the general regardless of party).

It's not surprising that Murray has decided to use her ad dollars attacking Rossi over the financial regulation bill. I've noted before that Democrats see this issue as a great way to accuse Republicans of being in bed with the Wall Street financiers who helped blow up the economy.

Republicans, for their part, are claiming that it's really Murray and other Democrats who are in the pocket of Wall Street. Rossi has a press release laying out the case, noting favorable comments for the bill from some Wall Street figures and criticizing Murray for voting for the bailouts of the financial and auto industries.

I am not going to untangle those arguments here. But it strikes me that all of these topics are complicated enough so that each side could cherry pick facts from here until November - and probably will. At this point, it's all about engaging voters' emotions, not their intellect.

With that in mind, for your viewing pleasure, here are the Murray and Rossi ads: